let nums = [1,3,-1,-1,5,3,6,7,]
var maxSlidingWindow = function(nums, k) {
    const len = nums.length
    const res =[]
    const deque = []
    for(let i = 0; i < len; i++){
        while(deque.length&& nums[deque[deque.length - 1]] < nums[i]){
            deque.pop()
        }
        deque.push(i)
        //当队列头部存放的值 和 i形成的区间大于窗口宽度时
        while(deque.length && deque[0] <= i-k){
            deque.shift()
        }
        //该取最大值
        if(i>=k -1){
            res.push(nums[deque[0]])
        }
    }
    return res
};